Print the stls (it should be obvious how many of each part). Lose a few pupils. Print replacements. Glue everything together, apart from the arms to the body. Once sanded down a little, the arms will click into the body, so they rotate but with enough friction to hold in place. Crash into people, and go POW!

The body was made with an inkscape dxf, rotate extruded in openscad. The sleeves and eyes were openscad and hacky. The really hard bit were the arms, these were in blender, then openscadded to add pins and to cut them in half so they're printable. A fun project for today :)

If anyone has improvements, I have a git repo here: github.com/JamesGlanville/bulletbill.git

Submit pull requests with impunity :)